溶菌酶功能化金纳米颗粒抑菌性能研究

Antimicrobial Activity of Lysozyme-Functionalized Gold Nanoparticles

为了提高溶菌酶的稳定性及对革兰氏阴性菌的抑菌性能,以金纳米颗粒为核,通过表面定向修饰溶菌酶,制备了绿色、高效的溶菌酶功能化金纳米颗粒抑菌材料,研究溶菌酶与金纳米的比例、纳米颗粒质量浓度等对抑菌效果的影响,研究溶菌酶功能化纳米材料对大肠杆菌的抑菌机理及对人神经母细胞瘤(SH-SY5Y)的细胞毒性。结果表明:与未修饰的金纳米及单纯的溶菌酶相比,溶菌酶功能化金纳米颗粒对大肠杆菌和金黄色葡萄球菌的抑菌效果均显著增强,表现出协同抑菌作用,在最优条件下,0.1 g/L溶菌酶功能化金纳米颗粒可以完全杀死2种细菌,并且该溶菌酶功能化金纳米颗粒具有持久抑菌性及良好的生物相容性,对哺乳细胞没有毒性。透射电子显微镜和活菌/死菌荧光染色结果表明:溶菌酶功能化金纳米颗粒主要通过破坏菌体细胞壁和细胞膜结构,从而杀死细菌。

In order to improve the stability of lysozyme and its antibacterial activity against Gram-negative bacteria,as a greenand highly efficient antibacterial agent,lysozyme-functionalized gold nanoparticles were prepared for the first time by surfacemodification of gold nanoparticles with lysozyme.The influences of the mass ratio of lysozyme to gold nanoparticles and theconcentration of functionalized nanoparticles on the antibacterial activity against Gram-negative and Gram-positive bacteria wereexamined.The antibacterial mechanism of the prepared materials against Escherichia coli and the cytotoxicity on SH-SY5Ycells were also investigated.The results showed that compared with pure gold nanoparticles and lysozyme,the antibacterialactivity of lysozyme-functionalized gold nanoparticles against E.coli and Staphylococcus aureus were obviously enhanced,which indicated the synergistic antibacterial effect of lysozyme and gold nanoparticles.Under optimized conditions,0.1g/Llysozyme-functionalized gold nanoparticles were able to completely kill the two types of bacteria.Besides,lysozymefunctionalizedgold nanoparticles exhibited durable antibacterial properties and good biocompatibility,which were not toxicto mammalian cells.Transmission electron microscopy(TEM)images and live/dead bacterial assay showed that lysozymefunctionalizedgold nanoparticles could kill bacteria by disrupting the cell membrane and cell wall.